Endplay and backlash really amount to the same thing in different
applications. The idea is that most mechanisms require "operating
clearance". This clearance can actually be as little as 0.00000001" but
there must be clearance throughout the entire range of movement or things
will start to go "all pear shaped" because the next step is "interference"
which is like "seized".
Because such variables as temperature expansion and machining tolerances
must be accommodated backlash or endplay is introduced so that under the
worst of conditions some clearance still exists.
In the steering box endplay, also known as end float, is adjusted by
removing shims from under the end cover of the steering box itself. The more
shims you remove the less end float the worm has in the steering box. The
trick is to remove just enough shims to eliminate virtually all the endplay.
(I should mention that usually, if a steering box needs this adjustment, the
bearing races on the worm will be damaged requiring a large injection of
Adjusting the rocker backlash is easier, but must be done with the steering
in the straight ahead position because there is a high spot on the steering
worm gear so that the minimum clearance occurs in the straight ahead
position. Adjust the screw and tighten the lock nut so that the screw is in
as far as possible with no perceivable drag as the steering is turned
through the center position.
From: firstname.lastname@example.org [mailto:email@example.com] On
Behalf Of Larry Swift
Sent: Monday, June 20, 2005 8:15 PM
Subject: Steering Question
On my BT7, there is about 6 inches of play in the steering wheel before
the front wheels begin to move. In reading the manual, it appears there
are 2 possible adjustments to the steering gear: one has to do with
endplay, the other is backlash. Endplay is a function of steering cam
bearing adjustment; backlash is addressed by adjusting the rocker shaft.
Unfortunately, I have no idea what endplay or backlash means and would
very much appreciate some advice on this subject.
Thanks very much,